40686689 has 4 divisors (see below), whose sum is σ = 40703124. Its totient is φ = 40670256.

The previous prime is 40686673. The next prime is 40686691. The reversal of 40686689 is 98668604.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 15936064 + 24750625 = 3992^2 + 4975^2 .

It is a cyclic number.

It is not a de Polignac number, because 40686689 - 2⁴ = 40686673 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (40686589) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3662 + ... + 9735.

It is an arithmetic number, because the mean of its divisors is an integer number (10175781).

Almost surely, 2^40686689 is an apocalyptic number.

It is an amenable number.

40686689 is a deficient number, since it is larger than the sum of its proper divisors (16435).

40686689 is a wasteful number, since it uses less digits than its factorization.

40686689 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16434.

The product of its (nonzero) digits is 497664, while the sum is 47.

The square root of 40686689 is about 6378.6118395776. The cubic root of 40686689 is about 343.9411320981.

The spelling of 40686689 in words is "forty million, six hundred eighty-six thousand, six hundred eighty-nine".